Combustion air feeding structure for oil-burning locomotives



Jan. 1, 1952 v. MANSFIELD COMBUSTION AIR FEEDING STRUCTURE FOR OILBURNING LOCOMOTIVES 2 SHEETSSHEET 1 Filed June 30, 1947 ENEEE g5: h fig-//v VEN r03 BY H a v. MANSFIELD 2,580,807" COMBUSTION AIR FEEDINGSTRUCTURE 0 FOR 011. BURNING LOCOMOTIVES Filed June 30, 1947 2SHEETSSHEET 2 Vaughn Mdnsfield I/VI/ENTOR IBYMHMP Patented Jan. 1, 1952UNITED STATE COMBUSTION AIR FEEDING STRUCTURE FOR OIL-BURNINGLOCOMOTIVES Vaughn Mansfield, Whitehaven, Tenn., assignor to MansfieldEngineering Company, Memphis, Tenn., a limited partnership of TennesseeApplication June at, 1947, Serial No. 758,060

2 Claims. (Cl. 110-76) This invention relates to air feeding systemsand, more particularly, to apparatus for feeding air-"to the combustionchamber of an oil fired locomotive.

' The primary object of this invention is to overcome the deleteriouseffects of the air stream passing a locomotive. In the usual locomotive,air is taken, through various inlets, into the combustion chamber forburning with the oil, the hot combustion gases then passing forwardlythrough the boiler tubes to the smoke box. Exhaust steam from thecylinders'is utilized for inducing, through a nozzle, the outfiow ofcombustion roducts from the smoke box. Itis thus apparent that theamount of air flowing through the combustion chamber depends primarilyon the contrast in pressures between the air inlets and the exhaustnozzle, and disproportionately high steam pressures have heretofore beennecessary for inducing the necessary contrast, resulting in high backpressures in the cylinders. Since the power output of the locomotivedepends upon the mean effective cylinder pressure, overall efficiencydepends to a surprisingly large extent on the cylinder back pressurerequired for inducing the air flow into the fire box. It has been foundthat turbulence in the fire box is essential to proper combustion of theoil and that an unusually high pressure differential has to bemaintained at the air inlets to create the desired furnace turbulence.The necessity for the unusually high diiferential at the conventionalair inlets is created by the deleterious efiects of eddy currents andwind velocities upon the side air inlets, rearwardly disposed airinlets, and because of confusing blasting by air from forwardly disposedinlets. The object now is to enshroud the lower portion of the fire boxof an oil fired locomotive with a plenum chamber, and to feed air, withminimum turbulence, to the plenum chamber. B this invention it isintended to assure proper distribution of air to the firebox throughvarious air openings of an oil fired locomotive firebox.

These and other objects will be apparent from the followingspecification and drawings, in which: I

Fig. 1 is a vertical longitudinal section through the fire box of an oilburning locomotive embodying the invention taken substantially along theline |--l of Fig. 2 looking in the direction of the arrows; and, Fig. 2is a vertical transverse section taken along the line 2-2 of Fig. 1looking in the direction of the arrows.

Before describing the invention, the structure typifying the fire box 2of a typical locomotive 4 will be briefed. This. includes a boiler shellhaving side walls 6, pan 8 lined with fire brick I 0, a'flash'wall' I2at the back end, lower and rear walls i4 and N5 of the boiler shell andan oil burner l8 which may partake of any one of several forms and bevariously located. While various arrangements'of air inlet openingsoccur, they generally include a set of forwardly directed apertures 20,air inlet tubes 22 through each side wall, a rearwardly opening hopper24 having an adjustable damper controlled, rearwardly facing opening 26,rearwardly directed inlets 28 through flash wall l2'connectingtheinterior of fire box 2 with an air space 30 open to the atmospherebehind the blank wall, and an air inlet 32 connecting via opening 34.Combustion products pass upwardly towards top 36 of the boiler shell andforwardly to the smoke box (not shown) through tubes 38. Generally, sideinlet tubes 22 have a flash guard (not shown) spaced beyond their outerends.

While the locomotive thus far described is standing or running at lowspeed, fairly uniform air entrance and distribution occurs. At highspeeds, or-'with a strong head wind, and cross winds, air blasts throughfrontal openings 20, shoots by side inlet tubes 22, and the physicalobstructions in front of openings 26 and 28 inter-' fere with proper airflow into the fire box through these ports.

The invention comprises a plenum chamber 40 having an outer casing 42surrounding the lower portion of fire box 2 and enshrouding openings 20,22, 26 and 28. Air is fed to chamber 40 through a trough 44 having aseries of transverse baflles 46 spaced therealong and preferablyextending across the trough and within the gap 48 between the lower edgeof the mud ring 5!! and trough bottom 52. One arrangement of the troughand baffles is disclosed in prior Mansfield Patent 2,415,256.

In the drawings the upper ends of the bafiles 46 are shown bent in aforward direction in order to facilitate scooping in of air, however, ifdesired, these baffles may be made straight as shown in my prior Patent2,445,256, granted February 4, 1947. The bafiles ili are also shown inthe drawings as extending to the bottom 52 of the trough 44, but it isevident that they may be made to stop short of the bottom of the trough44 in accordance with the construction shown in my prior patent,referred to above.

It should be'noted particularly that the effective height of bafiles 46increases from front to rear so that each baflle, except the first,overlaps 2,680,807 f .i :1 l1

and by combinations of the two arrangements.-

In any case, the increase in effective height of the baflies is suchthat each baflle 46 will catch and deflect the proper amount of air forthe space between it and the preceding bafiie.

While in the drawings the bafiies 48.are illus trated as equally spacedfrom one another, and the vertical distance that each bafile overlapsthe baiile immediately ahead of it is uniform through out thelongitudinal extent of trough 44, it is apparent that the bafiles may bespacedat difierent distances one from the other and the overand casingconstitute complete flash protection.

The invention is not limited to the specific structure detailed abovebut is intended to cover the modifications and adaptations within thescope of the following claims.

I claim:

1. In an oil burning locomotive having, in the lower rear portionthereof'front, rear, side and bottom walls, an oil burner encased withinsaid walls, each of said walls having air openings therethrough withoutwardly disposed inlet ends for feeding air inwardly to said oilburner, a caslapping distance of successive bailles may be.

varied in accordance with the amount of air it isdesired to interceptand introduce into diflerent areas considered longitudinally in thefirebox.

Whatever be the speed or force of the passing air stream, a generallyuniform inflow ofairv box 2 become substantially lower for proper air.

flow and a more uniform air distribution through all the inletsprevails.

It is apparent that casing 42 structures may be formed of sheet metalsimply by welding together a bottom sheet 53, front, rear, and sidesheets 54, 56 and 58, respectively, adding troughs and bafiiesconstructed generally in accordance with the prior patent (supra), andsubsequently installing, by obvious mechanical expedients the entireunit on the type of locomotive for which the unit was proportioned.Before installation of the unit, the flash guards customarily outsideside inlet tubes 22 may be removed since the chamber ing surrounding theabove-mentioned walls of said lower rear portion and spaced outwardlytherefrom whereby to form a plenum chamber common to said inlet ends andwhereby to shield the inlet ends from the passing airstream to whichthey otherwise would be exposed when the locomotive is in forwardmotion, and means at the sides of said casing and respectively adjacenteach side of the locomotive for admitting air 'to said plenum chamber.

, 2 The combination claimed in claim 1, said; means each comprising anL-shaped trough extending longitudinally of the fore-and-aft directionof the locomotive, said trough having an open top communicating with theatmosphere and an open inner side communicating with said chamber.

VAUGHN MANSFIELD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Date Mansfield Feb 4, 1947

